Conventionally, a solenoid valve is used for controlling supply and supply stop of compressed air for a pneumatic apparatus such as a pneumatic cylinder, and for controlling a pneumatic circuit for selecting and switching pneumatic circuits. An apparatus composed as an aggregation of two or more solenoid valves is referred to as “manifold solenoid valve”. There are two different types including an integrated type and a stacking type in this manifold solenoid valve. In the integrated type, an aggregation of two or more solenoid valves is carried out by mounting two or more solenoid valves on a large-sized manifold block formed with a common air supply flow passage and a common exhaust flow passage. On the other hand, the stacking type is also referred to as “divided type”, and an aggregation of two or more solenoid valves is carried out by mounting two or more solenoid valves on respective separated small manifold blocks, that is, mounting pedestals, and connecting the manifold blocks to each other.
One example of a stacking type manifold solenoid valve is disclosed in for example Patent Documents 1 and 2, the manifold solenoid valve has manifold blocks on which two or more solenoid valves are respectively mounted, and the manifold block has the shape of a rectangular parallelepiped. Each manifold block is provided with a mounting surface, that is, a mounting pedestal on which the solenoid valve is mounted, and formed with a passage via which air is flowed. The manifold solenoid valve is assembled by connecting manifold blocks adjacent to each other with a connecting member.